Predictions of Gamma-ray Emission from Globular Cluster Millisecond Pulsars Above 100 MeV

TL;DR

This paper models gamma-ray emissions from millisecond pulsars in globular clusters, predicting detectable signals for Fermi and providing constraints on pulsar populations and magnetic fields.

Contribution

It introduces combined pulsed curvature radiation and unpulsed inverse Compton models for MSPs in globular clusters, offering new predictions for gamma-ray detection.

Findings

CR from GCs should be detectable by Fermi

IC flux constrains MSP population size

IC flux constrains nebular magnetic field

Abstract

The recent Fermi detection of the globular cluster (GC) 47 Tucanae highlighted the importance of modeling collective gamma-ray emission of millisecond pulsars (MSPs) in GCs. Steady flux from such populations is also expected in the very high energy (VHE) domain covered by ground-based Cherenkov telescopes. We present pulsed curvature radiation (CR) as well as unpulsed inverse Compton (IC) calculations for an ensemble of MSPs in the GCs 47 Tucanae and Terzan 5. We demonstrate that the CR from these GCs should be easily detectable for Fermi, while constraints on the total number of MSPs and the nebular B-field may be derived using the IC flux components.